1. Field of the Invention
The present invention relates to a test fixture for a nozzle of an aircraft fueling system and more particularly to a test fixture for sensing excessive wear on aircraft fueling nozzles.
2. Description of the Prior Art
Typical aircraft fueling nozzle structures are provided with a poppet type fluid control valve. The valve is disposed at the outlet end of the fuel source for connection to a fueling flange or adapter on an aircraft and at the inlet end of a connection to a fuel supply hose. The poppet of the valve has a head and a stem which is guided for reciprocal movement in the valve body. The valve is actuated by linkage which includes an arm rotatably connected to the valve stem, a crank connected to the arm and means for actuating the crank, such as a hand operated lever connected to the crank by means of a shaft, for example.
In one typical design, a single crank is used with two arms, one at either side of the crank and valve stem. The arms are connected to the crank by an axle pin and connected to the valve stem by a second axle pin extending through the stem. With the crank disposed adjacent the inlet end of the nozzle body, the arms extend downstream toward the outlet end, where they are connected to an end of the valve stem. The poppet is mounted to the other end of the valve stem.
The valve seat is supported and typically biased toward the poppet head by suitable spring means to normally provide a sealing relation between the poppet and the valve seat. Operation is mechanical through manual control. The poppet type valve seals the nozzle outlet against leakage of fuel when not attached to a mating adapter aboard an aircraft, for example. The control for the valve is locked against operation until after the nozzle has been coupled to the adapter. When the nozzle has been coupled to the associated adapter, the nose-seal of the nozzle is compressed against the sealing surface of a bayonet type flange of the adapter to form a fluid-tight connection between the nozzle and the adapter. When this connection is suitably achieved, the valve flow control handle is unlocked so that subsequent rotation of the handle effectively lifts the poppet valve head from its seat thus opening a passageway for fuel to flow from the nozzle to the aircraft through the adapter.
In a nozzle assembly manufactured by Whittaker Controls, Inc., North Hollywood, Calif. 91605, the nozzle is provided with a connector for mating with a fueling flange of an aircraft. The fueling flange has an annular rim with three radially outwardly projecting lugs and three slots intermediate the lugs. The connector has three ramps interspaced with three slots, which are configured to receive the fueling flange lugs. When the nozzle is mated with the fueling flange, the lugs are adapted to pass through the slots as the flange depresses an associated spring loaded interlock plate. The flange is secured to the nozzle to avoid any relative rotation by pins which are attached to the nozzle body and extend into the slots on the fueling flange. When the interlock plate is depressed, the connector may be rotated so that the lugs are secured beneath the ramps thereby firmly connecting the flange to the nozzle and unlocking the crank arm to permit the opening of the poppet valve to allow for the flow of the pressurized fuel therethrough.
However, after extended use, it has been found that excessive wear occurs allowing the nozzle to be opened when it is not connected to an adapter on an aircraft or a refueling vehicle. Obviously, such leakage and spillage are particularly undesirable and dangerous when the fluid being handled is reactive, flammable, electrically conductive, noxious, toxic, and creates a slippery area adversely effecting transient traffic.
Accordingly, it is an object of the present invention to produce a test fixture enabling the testing of aircraft fueling nozzles for excessive wear.
The above object may typically be achieved by a test fixture for an interlock plate of a fueling nozzle comprising a main body, the body having an annular rib projecting outwardly therefrom, the rib provided with spaced apart slots, whereby the annular rib may depress an interlock plate an amount equal to the depth of the slots.